A motor control system of power tools generally includes a large capacity capacitor. When a battery pack is connected with the power tool, the voltage at the capacitor is low, the battery pack charges the capacitor, and a large current is generated at the moment of charging. As a result, an electric spark may be generated at the connection pieces, which may corrode the connection pieces.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.